The present disclosure is related generally to the fabrication of semiconductor devices, and, more particularly, to a metal-insulator-metal (MIM) structure, a method of manufacturing the structure, and a semiconductor device incorporating the structure.
Capacitors are critical components for many data manipulation and data storage applications. In general, capacitors include two conductive electrodes on opposing sides of a dielectric or other insulating layer, and they may be categorized based on the materials employed to form the electrodes. For example, in a metal-insulator-metal (MIM) capacitor, the electrodes substantially comprise metal. MIM capacitors offer the advantage of a relatively constant value of capacitance over a relatively wide range of voltages applied thereto. MIM capacitors also exhibit a relatively small parasitic resistance.
Generally, it is desirable that MIM capacitors (and others) consume as little surface area as possible to increase packing density. At the same time, capacitance values should be maximized to obtain optimum device performance, such as when employed for data retention in dynamic random access memory (DRAM) applications or for decoupling in mixed-signal and microprocessor applications. However, capacitance values for a single capacitor generally decrease as the surface area of the capacitor decreases. Various structures have been proposed in attempt to overcome this dichotomy between minimizing capacitor structure size and maximizing capacitance values. One such example is a crown-shaped capacitor, which resembles a folded structure in which a trench is lined with a first electrode and filled with an annular shaped insulating element and an inner core electrode, thereby increasing the effective electrode contact area relative to conventional planar capacitors. Although crown capacitors have been satisfactory for its intended purpose, they have not been satisfactory in all respects.